Aromatics alkylation

ABSTRACT

The present invention provides a process for producing an alkylaromatic compound comprising the step of contacting an alkylatable aromatic compound with an alkylating agent under alkylation conditions in the presence of a alkylation catalyst comprising phosphorus and a porous crystalline inorganic oxide material having an X-ray diffraction pattern including the d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstrom.

BACKGROUND OF THE INVENTION

The present invention relates to aromatics alkylation, and in particularto the alkylation of benzene with ethylene and propylene to produceethylbenzene and cumene, respectively. In addition, the invention isconcerned with the alkylation of aromatics with long chain (C₆+)alkylating agents to produce long chain alkylbenzenes.

Ethylbenzene and cumene are valuable commodity chemicals which are usedindustrially for the production of styrene monomer and phenol,respectively. In addition, long chain alkylbenzenes are useful aslubricant base stocks and as intermediates in the production ofdetergents.

Alkylation is one of the most important and useful reactions ofhydrocarbons. Lewis and Bronsted acids, including a variety of naturaland synthetic zeolites, have been used as alkylation catalysts.Alkylation of aromatic hydrocarbon compounds employing certaincrystalline zeolite catalysts is known in the art. In particular,alkylation of benzene with ethylene and propylene in the presence ofzeolite catalysts represents the preferred commercial techniques for theproduction of ethylbenzene and cumene.

For example, U.S. Pat. No. 4,992,606 describes the use of MCM-22 in thealkylation of aromatic compounds, such as benzene, with alkylatingagents having aliphatic groups with 1 to 5 carbon atoms, such asethylene and propylene. Similarly, U.S. Pat. No. 4,962,256 describes theuse of MCM-22 in the alkylation of aromatic compounds with alkylatingagents having aliphatic groups with at least 6 carbon atoms.

The use of MCM-49 in the alkylation of aromatic compounds with shortchain alkylating agents is described in U.S. Pat. No. 5,371,310 and inalkylation of aromatic compounds with long chain alkylating agents isdescribed in U.S. Pat. No. 5,401,896.

The use of MCM-56 in the alkylation of aromatic compounds with shortchain alkylating agents is described in U.S. Pat. Nos. 5,453,554 and5,557,024.

It is also known from U.S. Pat. No. 5,470,810 that the addition ofphosphorus to MCM-22 improves the hydrothermal stability of theresulting catalyst for use in catalytic cracking.

U.S. Pat. No. 3,962,364 discloses that the addition of at least 0.5 wt %phosphorus to a zeolite having a constraint index of 1-12, in particularZSM-5, increases the selectivity of the zeolite in the vapor phasealkylation of aromatic hydrocarbons with olefins.

According to the invention, it has now been found that modification ofMCM-22 and certain related molecular sieve catalysts, such as MCM-49 andMCM-56, with phosphorus increases the activity of the catalyst for thealkylation of aromatic compounds. In addition, the phosphorusmodification increases the selectivity of the catalyst towards themonoalkylated product and enhances its stability against thehydrothermal deactivation which can occur during regeneration.

SUMMARY OF THE INVENTION

According to the invention, there is provided a process for producing analkylaromatic compound comprising the step of contacting an alkylatablearomatic compound with an alkylating agent under alkylation conditionsin the presence of an alkylation catalyst comprising phosphorus and aporous crystalline inorganic oxide material having an X-ray diffractionpattern including the d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07and 3.42±0.07 Angstrom.

Preferably, the porous crystalline inorganic oxide material is selectedfrom the group consisting of MCM-22, PSH-3, SSZ-25, MCM-36, MCM-49 andMCM-56.

Preferably, the alkylating agent has an aliphatic group having 1 to 5carbon atoms.

Preferably, the aromatic hydrocarbon is benzene and the alkylating agentis selected from ethylene and propylene.

Preferably, said alkylation conditions are such as to maintain saidalkylatable aromatic compound substantially in the liquid phase.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a process for the production of analkylaromatic compound, particularly ethylbenzene or cumene, by thealkylation of an alkylatable aromatic compound, particularly benzene,with an alkylating agent, particularly ethylene or propylene, underalkylation conditions with a phosphorus-containing porous crystallineinorganic oxide material having an X-ray diffraction pattern includingthe d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07Angstrom.

The term “aromatic” in reference to the alkylatable compounds which areuseful herein is to be understood in accordance with its art-recognizedscope which includes alkyl substituted and unsubstituted mono- andpolynuclear compounds. Compounds of an aromatic character which possessa hetero atom are also useful provided they do not act as catalystpoisons under the reaction conditions selected.

Substituted aromatic compounds which can be alkylated herein mustpossess at least one hydrogen atom directly bonded to the aromaticnucleus. The aromatic rings can be substituted with one or more alkyl,aryl, alkaryl, alkoxy, aryloxy, cycloalkyl, halide, and/or other groupswhich do not interfere with the alkylation reaction.

Suitable aromatic hydrocarbons include benzene, naphthalene, anthracene,naphthacene, perylene, coronene, and phenanthrene, with benzene beingpreferred.

Generally the alkyl groups which can be present as substituents on thearomatic compound contain from 1 to about 22 carbon atoms and usuallyfrom about 1 to 8 carbon atoms, and most usually from about 1 to 4carbon atoms.

Suitable alkyl substituted aromatic compounds include toluene, xylene,isopropylbenzene, normal propylbenzene, alpha-methylnaphthalene,ethylbenzene, cumene, mesitylene, durene, p-cymene, butylbenzene,pseudocumene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene,isoamylbenzene, isohexylbenzene, pentaethylbenzene, pentamethylbenzene;1,2,3,4-tetraethylbenzene; 1,2,3,5-tetramethylbenzene;1,2,4-triethylbenzene; 1,2,3-trimethylbenzene, m-butyltoluene;p-butyltoluene; 3,5-diethyltoluene; o-ethyltoluene; p-ethyltoluene;m-propyltoluene; 4-ethyl-m-xylene; dimethylnaphthalene;ethylnaphthalene; 2,3-dimethylanthracene; 9-ethylanthracene;2-methylanthracene; o-methylanthracene; 9,10-dimethylphenanthrene; and3-methyl-phenanthrene. Higher molecular weight alkylaromatichydrocarbons can also be used as starting materials and include aromatichydrocarbons such as are produced by the alkylation of aromatichydrocarbons with olefin oligomers. Such products are frequentlyreferred to in the art as alkylate and include hexylbenzene,nonylbenzene, dodecylbenzene, pentadecylbenzene, hexyltoluene,nonyltoluene, dodecyltoluene and pentadecyltoluene. Very often alkylateis obtained as a high boiling fraction in which the alkyl group attachedto the aromatic nucleus varies in size from about C₆ to about C₁₂. Whencumene or ethylbenzene is the desired product, the present processproduces acceptably little by-products such as xylenes. The xylenes makein such instances may be less than about 500 ppm.

Reformate containing substantial quantities of benzene, toluene and/orxylene constitutes a particularly useful feed for the alkylation processof this invention.

The alkylating agents which are useful in the process of this inventiongenerally include any aliphatic or aromatic organic compound having oneor more available alkylating aliphatic groups capable of reaction withthe alkylatable aromatic compound.

Preferably, the alkylating agent employed herein has at least onealkylating aliphatic group possessing from 1 to 5 carbon atoms. Examplesof such alkylating agents are olefins such as ethylene, propylene, thebutenes, and the pentenes; alcohols (inclusive of monoalcohols,dialcohols and trialcohols) such as methanol, ethanol, the propanols,the butanols, and the pentanols; aldehydes such as formaldehyde,acetaldehyde, propionaldehyde, butyraldehyde, and n-valeraldehyde; andalkyl halides such as methyl chloride, ethyl chloride, the propylchlorides, the butyl chlorides and the pentyl chlorides.

Mixtures of light olefins are especially useful as alkylating agents inthe alkylation process of this invention. Accordingly, mixtures ofethylene, propylene, butenes, and/or pentenes which are majorconstituents of a variety of refinery streams, e.g., fuel gas, gas plantoff-gas containing ethylene, propylene, etc., naphtha cracker off-gascontaining light olefins and refinery FCC propane/propylene streams, areuseful alkylating agents herein. For example, a typical FCC light olefinstream possesses the following composition:

Wt. % Mole % Ethane 3.3 5.1 Ethylene 0.7 1.2 Propane 4.5 15.3 Propylene42.5 46.8 Isobutane 12.9 10.3 n-Butane 3.3 2.6 Butenes 22.1 18.32Pentanes 0.7 0.4

Reaction products which may be obtained from the process of theinvention using short chain (C₁-C₅) alkylating agents includeethylbenzene from the reaction of benzene with ethylene, cumene from thereaction of benzene with propylene, ethyltoluene from the reaction oftoluene with ethylene, cymenes from the reaction of toluene withpropylene, and sec-butylbenzene from the reaction of benzene andn-butenes.

Alternatively, the alkylating agent used in the process of the inventionhas one or more alkylating aliphatic groups with at least about 6 carbonatoms, preferably at least about 8, and still more preferably at leastabout 12 carbon atoms. Examples of suitable long chain alkylating agentsare olefins such as hexenes, heptenes, octenes, nonenes, decenes,undecenes and dodecenes; alcohols (inclusive of monoalcohols,dialcohols, and trialcohols) such as hexanols, heptanols, octanols,nonanols, decanols, undecanols and dodecanols; and alkyl halides such ashexyl chlorides, octyl chlorides, dodecyl chlorides; and, higherhomologs of the foregoing. Branched alkylating agents, especiallyoligomerized olefins such as the trimers, tetramers and pentamers, oflight olefins, such as ethylene, propylene and butylenes, are alsouseful herein.

The alkylation catalyst used in the process of the invention comprisesphosphorus and a porous crystalline inorganic oxide material having anX-ray diffraction pattern including d-spacing maxima at 12.4±0.25,6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstrom. The X-ray diffraction dataused throughout this specification were obtained by standard techniquesusing the K-alpha doublet of copper as the incident radiation and adiffractometer equipped with a scintillation counter and associatedcomputer as the collection system.

Suitable porous crystalline inorganic oxide materials are MCM-22(described in U.S. Pat. No. 4,954,325), PSH-3 (described in U.S. Pat.No. 4,439,409), SSZ-25 (described in U.S. Pat. No. 4,826,667), MCM-36(described in U.S. Pat. No. 5,250,277), MCM-49 (described in U.S. Pat.No. 5,236,575) and MCM-56 (described in U.S. Pat. No. 5,362,697). Allthe above U.S. patents are incorporated herein by reference.

The alkylation catalyst used in the process of the invention alsocontains phosphorus. The amount of phosphorus, as measured on anelemental basis, may be between about 0.05 and about 10 wt. %,preferably between about 0.1 and about 2 wt. %, and most preferablybetween about 0.1 and about 0.5 wt. %, based on the weight of the finalcatalyst.

Incorporation of the phosphorus modifier into the catalyst of theinvention is conveniently achieved by the methods described in U.S. Pat.Nos. 4,356,338, 5,110,776 and 5,231,064, the entire disclosures of whichare incorporated herein by reference. Treatment withphosphorus-containing compounds can readily be accomplished bycontacting the porous crystalline material, either alone or incombination with a binder or matrix material, with a solution of anappropriate phosphorus compound, followed by drying and calcining toconvert the phosphorus to its oxide form. Contact with thephosphorus-containing compound is generally conducted at a temperatureof about 25° C. and about 125° C. for a time between about 15 minutesand about 20 hours. The concentration of the phosphorus in the contactmixture may be between about 0.01 and about 30 wt. %.

Representative phosphorus-containing compounds which may be used includederivatives of groups represented by PX₃, RPX₂, R₂PX, R₃P, X₃PO,(XO)₃PO, (XO)₃P, R₃P═O, R₃P═S, RPO₂, RPS₂, RP(O)(OX)₂, RP(S)(SX)₂,R₂P(O)OX, R₂P(S)SX, RP(OX)₂, RP(SX)₂, ROP(OX)₂, RSP(SX)₂, (RS)₂PSP(SR)₂,and (RO)₂POP(OR)₂, where R is an alkyl or aryl, such as phenyl radical,and X is hydrogen, R, or halide. These compounds include primary, RPH₂,secondary, R₂PH, and tertiary, R₃P, phosphines such as butyl phosphine,the tertiary phosphine oxides, R₃PO, such as tributyl phosphine oxide,the tertiary phosphine sulfides, R₃PS, the primary, RP(O)(OX)₂, andsecondary, R₂P(O)OX, phosphonic acids such as benzene phosphonic acid,the corresponding sulfur derivatives such as RP(S)(SX)₂ and R₂P(S)SX,the esters of the phosphonic acids such as dialkyl phosphonate,(RO)₂P(O)H, dialkyl alkyl phosphonates, (RO)₂P(O)R, and alkyldialkylphosphinates, (RO)P(O)R₂; phosphinous acids, R₂POX, such asdiethylphosphinous acid, primary, (RO)P(OX)₂, secondary, (RO)₂POX, andtertiary, (RO)₃P, phosphites, and esters thereof such as the monopropylester, alkyl dialkylphosphinites, (RO)PR₂, and dialkyl alkyphosphinites,(RO)₂PR. Corresponding sulfur derivatives may also be employed including(RS)₂P(S)H, (RS)₂P(S)R, (RS)P(S)R₂, R₂PSX, (RS)P(SX)₂, (RS)₂PSX, (RS)₃P,(RS)PR₂, and (RS)₂PR. Examples of phosphite esters includetrimethylphosphite, triethylphosphite, diisopropylphosphite,butylphosphite, and pyrophosphites such as tetraethylpyrophosphite. Thealkyl groups in the mentioned compounds preferably contain one to fourcarbon atoms.

Other suitable phosphorus-containing compounds include ammonium hydrogenphosphate, the phosphorus halides such as phosphorus trichloride,bromide, and iodide, alkyl phosphorodichloridites, (RO)PCl₂,dialkylphosphorochloridites, (RO)₂PCl, dialkylphosphinochloridites,R₂PCl, alkyl alkylphosphonochloridates, (RO)(R)P(O)Cl, dialkylphosphinochloridates, R₂P(O)Cl, and RP(O)Cl₂. Applicable correspondingsulfur derivatives include (RS)PCl₂, (RS)₂PCl, (RS)(R)P(S)Cl, andR₂P(S)Cl.

Particular phosphorus-containing compounds include ammonium phosphate,ammonium dihydrogen phosphate, diammonium hydrogen phosphate, diphenylphosphine chloride, trimethylphosphite, phosphorus trichloride,phosphoric acid, phenyl phosphine oxychloride, trimethylphosphate,diphenyl phosphinous acid, diphenyl phosphinic acid,diethylchlorothiophosphate, methyl acid phosphate, and otheralcohol-P₂O₅ reaction products.

After contacting with the phosphorus-containing compound, the catalystmay be dried and calcined to convert the phosphorus to an oxide form.Calcination can be carried out in an inert atmosphere or in the presenceof oxygen, for example, in air at a temperature of about 150 to 750° C.,preferably about 300 to 500° C., for at least 1 hour, preferably 3-5hours.

The porous crystalline oxide material employed in the alkylationcatalyst of the invention may be combined with a variety of binder ormatrix materials resistant to the temperatures and other conditionsemployed in the process. Such materials include active and inactivematerials such as clays, silica and/or metal oxides such as alumina. Thelatter may be either naturally occurring or in the form of gelatinousprecipitates or gels including mixtures of silica and metal oxides. Useof a material which is active, tends to change the conversion and/orselectivity of the catalyst and hence is generally not preferred.Inactive materials suitably serve as diluents to control the amount ofconversion in a given process so that products can be obtained in aneconomical and orderly manner without employing other means forcontrolling the rate of reaction. These materials may be incorporatedinto naturally occurring clays, e.g., bentonite and kaolin, to improvethe crush strength of the catalyst under commercial operatingconditions. Said materials, i.e., clays, oxides, etc., function asbinders for the catalyst. It is desirable to provide a catalyst havinggood crush strength because in commercial use it is desirable to preventthe catalyst from breaking down into powder-like materials. These clayand/or oxide binders have been employed normally only for the purpose ofimproving the crush strength of the catalyst.

Naturally occurring clays which can be composited with the porouscrystalline material include the montmorillonite and kaolin family,which families include the subbentonites, and the kaolins commonly knownas Dixie, McNamee, Georgia and Florida clays or others in which the mainmineral constituent is halloysite, kaolinite, dickite, nacrite, oranauxite. Such clays can be used in the raw state as originally mined orinitially subjected to calcination, acid treatment or chemicalmodification.

In addition to the foregoing materials, the porous crystalline materialcan be composited with a porous matrix material such as silica-alumina,silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia,silica-titania as well as ternary compositions such assilica-alumina-thoria, silica-alumina-zirconia silica-alumina-magnesiaand silica-magnesia-zirconia.

The relative proportions of zeolite and inorganic oxide matrix varywidely, with the content of the former ranging from about 1 to about 90%by weight and more usually, particularly when the composite is preparedin the form of beads, in the range of about 2 to about 80 wt. % of thecomposite.

The alkylation process of this invention is conducted such that theorganic reactants, i.e., the alkylatable aromatic compound and thealkylating agent, are brought into contact with an alkylation catalystin a suitable reaction zone such as, for example, in a flow reactorcontaining a fixed bed of the catalyst composition, under effectivealkylation conditions. Such conditions include a temperature of fromabout 0° C. to about 500° C., and preferably between about 50° C. andabout 250° C., a pressure of from about 0.2 to about 250 atmospheres,and preferably from about 5 to about 100 atmospheres, a molar ratio ofalkylatable aromatic compound to alkylating agent of from about 0.1:1 toabout 50:1, and preferably can be from about 0.5:1 to about 10:1, and afeed weight hourly space velocity (WHSV) of between about 0.1 and 500hr⁻¹, preferably between 0.5 and 100 hr⁻¹.

The reactants can be in either the vapor phase or the liquid phase andcan be neat, i.e., free from intentional admixture or dilution withother material, or they can be brought into contact with the zeolitecatalyst composition with the aid of carrier gases or diluents such as,for example, hydrogen or nitrogen. Preferably, the alkylation conditionsare such as to maintain the alkylatable aromatic compound substantiallyin the liquid phase. For example, the alkylation reaction can beconducted by reactive distillation.

When benzene is alkylated with ethylene to produce ethylbenzene, thepreferred catalyst is phosphorus-modified MCM-22 and alkylation reactionis preferably carried out in the liquid phase. Suitable liquid phaseconditions include a temperature between 300° F. and 600° F. (about 150°C. and 316° C.), preferably between 400° F. and 500° F. (about 205° C.and 260° C.), a pressure up to about 3000 psig (20875 kPa), preferablybetween 400 and 800 psig (2860 and 5600 kPa), a space velocity betweenabout 0.1 and 20 WHSV, preferably between 1 and 6 WHSV, based on theethylene feed, and a ratio of the benzene to the ethylene in thealkylation reactor from 1:1 to 30:1 molar, preferably from about 1:1 to10:1 molar.

When benzene is alkylated with propylene to produce cumene, thepreferred catalyst is phosphorus-modified MCM-49 or phosphorus-modifiedMCM-56. The alkylation reaction is also preferably conducted underliquid phase conditions including a temperature of up to about 250° C.,e.g., up to about 150° C., e.g., from about 10° C. to about 125° C.; apressure of about 250 atmospheres or less, e.g., from about 1 to about30 atmospheres; and an aromatic hydrocarbon weight hourly space velocity(WHSV) of from about 5 hr⁻¹ to about 250 hr⁻¹, preferably from 5 hr⁻¹ to50 hr⁻¹.

The use of the phosphorus modifier in the alkylation catalyst of theinvention is found to enhance the alkylation activity of the catalystover a wide range of aromatic compound to alkylating agent molar ratios,thereby allowing operation at higher space velocities and henceincreasing production capacity. In addition, the presence of thephosphorus is found to increase the selectivity of the catalyst for theproduction of the desired monoalkylated product and decrease itsselectivity for the production of polyalkylated products. Further, thephosphorus modification may increase the hydrothermal stability of thecatalyst, thereby enhancing its regenerability.

The alkylation reactor effluent contains the excess aromatic feed,monoalkylated product, polyalkylated products, and various impurities.The aromatic feed is recovered by distillation and recycled to thealkylation reactor. Usually a small bleed is taken from the recyclestream to eliminate unreactive impurities from the loop. The bottomsfrom the aromatic distillation are further distilled to separatemonoalkylated product from polyalkylated products and other heavies.

Additional monoalkylated product may be produced by transalkylation. Thepolyalkylated products may be recycled to the alkylation reactor toundergo transalkylation or they may be reacted with additional aromaticfeed in a separate reactor. It may be preferred to blend the bottomsfrom the distillation of monoalkylated product with a stoichiometricexcess of the aromatic feed, and react the mixture in a separate reactorover a suitable transalkylation catalyst. The transalkylation catalystmay be a catalyst comprising a zeolite such as MCM-36, MCM-49, MCM-56,MCM-22, PSH-3, SSZ-25, zeolite X, zeolite Y, zeolite beta, or mordenite.Such transalkylation reactions over zeolite beta are disclosed in theaforementioned U.S. Pat. No. 4,891,458; and further suchtransalkylations using an acid dealuminized mordenite are disclosed inU.S. Pat. No. 5,243,116. Another particular form of mordenite, which maybe used as a transalkylation catalyst, is TEA mordenite, i.e., syntheticmordenite prepared from a reaction mixture comprising atetraethylammonium directing agent. TEA mordenite is disclosed in U.S.Pat. Nos. 3,766,093 and 3,894,104. The effluent from the transalkylationreactor is blended with alkylation reactor effluent and the combinedstream distilled. A bleed may be taken from the polyalkyated productstream to remove unreactive heavies from the loop or the polyalkyatedproduct stream may be distilled to remove heavies prior totransalkylation.

The invention will be described with reference to the followingExamples.

EXAMPLE 1 Ethylbenzene Synthesis from Benzene and Ethylene OverUnmodified MCM-22

An MCM-22 catalyst was prepared as a 65/35 extrudate with 65 wt. %MCM-22 crystal with 35 wt % alumina. One gram of the catalyst wascharged to an isothermal, well-mixed Parr autoclave reactor along with amixture comprising of benzene (195 g) and ethylene (20 g). The reactionwas carried out at 428° F. and 550 psig for 4 hours. A small sample ofthe product was withdrawn at regular intervals and analyzed by gaschromatography. The catalyst performance was assessed by a kineticactivity rate constant based on ethylene conversion and by theethylbenzene selectivity at 100% ethylene conversion. The results forthe kinetic activity rate constant are given in Table 1 and for theethylbenzene selectivity are given in Table 2.

EXAMPLE 2 Ethylbenzene Synthesis from Benzene and Ethylene Over MCM-22Modified with Phosphorous Impregnated Via Phosphoric Acid (H₃PO₄)Solution

0.1-10 grams of H₃PO₄ were dissolved in 50 grams of distilled water toyield a solution of pH ranging from 3.1 to 6.9. The resulting solutionwas used to impregnate fifty grams of a fresh sample of the MCM-22catalyst used in Example 1 by an incipient wetness method. Theimpregnated catalyst was dried at 250° F. for 12 hours in air followedby calcination at a temperature between 400 and 1200° F. in flowing airfor 4 hours. The resulting phosphorus weight loading varied from 0.5% to5%. One gram of the final catalyst was evaluated for benzene alkylationwith ethylene according to the procedure described in Example 1.Catalyst performance is compared with that of the unmodified MCM-22 ofExample 1 in Tables 1 and 2.

EXAMPLE 3 Ethylbenzene Synthesis from Benzene and Ethylene Over MCM-22Modified with Phosphorous Impregnated Via Dibasic Ammonium Phosphate((NH₄)₂HPO₄) Solution

0.1-10 grams of (NH₄)₂HPO₄ were dissolved in 50 grams of distilled waterto yield a solution of pH ranging from 4.9 to 7.1. The resultingsolution was used to impregnate fifty grams of a fresh sample of theMCM-22 catalyst used in Example 1 by an incipient wetness method. Theimpregnated catalyst was dried at 250° F. for 12 hours in air followedby calcination at a temperature between 400 and 1200° F. in flowing airfor 4 hours. The resulting phosphorus weight loading varied from 0.5% to5%. One gram of the final catalyst was evaluated for benzene alkylationwith ethylene according to the procedure described in Example 1.Catalyst performance is compared with that of the unmodified MCM-22 ofExample 1 in Tables 1 and 2.

EXAMPLE 4 Comparison of Catalyst Performance

The performance of MCM-22 modified with phosphorous impregnated via ananionic precursor such as phosphoric acid (H₃PO₄) or dibasic ammoniumphosphate ((NH₄)₂HPO₄) is compared with unmodified MCM-22 in Tables 1and 2 below. The data in Table 1 represent kinetic rate constantsevaluated based upon ethylene conversion in the autoclave according tothe procedure outlined in Example 1. It will be seen from Table 1 thatthe modification of the MCM-22 with phosphorus increased its activityfor benzene alkylation with ethylene by 27% in Example 2 and by 37% inExample 3.

TABLE 1 Catalyst Example 1 Example 2 Example 3 Kinetic Rate Constant 4152 56

The data in Table 2 represent the ethylbenzene selectivity at 100%ethylene conversion according to the procedure outlined in Example 1. Itwill be seen from Table 2 that the modification of the MCM-22 withphosphorus increased its selectivity for ethylbenzene production bydecreasing its selectivity to diethylbenzene (by 12% in Example 2 and by18% in Example 3) and by decreasing its selectivity to triethylbenzene(by 14% in Example 2 and by 29% in Example 3).

TABLE 2 Ethyl- Reduction Reduction benzene DiEB/EB TriEB/EB in DiEB, inTriEB, Catalyst (EB) wt. % wt. % wt. % wt. % wt. % Example 1 91.9 8.50.35 Example 2 92.8 7.5 0.3 11.7 14.2 Example 3 93.3 7 0.25 17.6 28.5

EXAMPLE 5 Cumene Synthesis from Benzene and Propylene Over UnmodifiedMCM-56

MCM-56 catalyst was prepared as a 65/35 extrudate with 65 wt % MCM-56crystal with 35 wt % alumina. One gram of the catalyst was charged to anisothermal well-mixed Parr autoclave reactor along with a mixturecomprising of benzene (156 g) and propylene (28 g). The reaction wascarried out at 266° F. and 300 psig for 4 hours. A small sample of theproduct was withdrawn at regular intervals and analyzed by gaschromatography. The catalyst performance was assessed by a kineticactivity rate constant based on propylene conversion and cumeneselectivity at 100% propylene conversion. The results are given inTables 3 and 4.

EXAMPLE 6 Cumene Synthesis from Benzene and Propylene Over MCM-56Modified with 0.1 wt. % Phosphorus Impregnated Via Phosphoric Acid(H₃PO₄) Solution

0.2 grams of H₃PO₄ were dissolved in 50 grams of distilled water, andthe resulting solution was used to impregnate fifty grams of a freshsample of the MCM-56 used in Example 5 by an incipient wetness method.The impregnated catalyst was dried at 250° F. for 12 hours in airfollowed by calcination at 400° F. in flowing air for 4 hours, resultingin 0.1 wt. % P-loading. One gram of the final catalyst was evaluated forbenzene alkylation with propylene according to the procedure describedin Example 5. Catalyst performance is compared with that of unmodifiedMCM-56 in Table 3.

EXAMPLE 7 Cumene Synthesis from Benzene and Propylene Over MCM-56Modified with 0.5 wt. % Phosphorus Impregnated Via Phosphoric Acid(H₃PO₄) Solution

1.0 grams of H₃PO₄ were dissolved in 50 grams of distilled water and theresulting solution was used to impregnate fifty grams of a fresh sampleof the MCM-56 used in Example 5 by an incipient wetness method. Theimpregnated catalyst was dried at 250° F. for 12 hours in air followedby calcination at 400° F. in flowing air for 4 hours, resulting in 0.5wt. % P-loading. One gram of the final catalyst was evaluated forbenzene alkylation with propylene according to the procedure describedin Example 5. Catalyst performance is compared with that of unmodifiedMCM-56 in Table 3.

EXAMPLE 8 Cumene Synthesis from Benzene and Propylene Over MCM-56Modified with 1.0 wt. % Phosphorus Impregnated Via Phosphoric Acid(H₃PO₄) Solution

2.0 grams of H₃PO₄ were dissolved in 50 grams of distilled water, andthe resulting solution was used to impregnate fifty grams of a freshsample of MCM-56 used in Example 5 by an incipient wetness method. Theimpregnated catalyst was dried at 250° F. for 12 hours in air followedby calcination at 400° F. in flowing air for 4 hours, resulting in 1.0wt. % P-loading. One gram of the final catalyst was evaluated forbenzene alkylation with propylene according to the procedure describedin Example 5. Catalyst performance is compared with that of unmodifiedMCM-56 in Table 3.

EXAMPLE 9 Cumene Synthesis from Benzene and Propylene Over MCM-56Modified with 2.0 wt. % Phosphorus Impregnated Via Phosphoric Acid(H₃PO₄) Solution

4.0 grams of H₃PO₄ were dissolved in 50 grams of distilled water, andthe resulting solution was used to impregnate fifty grams of a freshsample of MCM-56 used in Example 5 by an incipient wetness method. Theimpregnated catalyst was dried at 250° F. for 12 hours in air followedby calcination at 400° F. in flowing air for 4 hours, resulting in 2.0wt. % P-loading. One gram of the final catalyst was evaluated forbenzene alkylation with propylene according to the procedure describedin Example 5. Catalyst performance is compared with that of unmodifiedMCM-56 in Table 3.

EXAMPLE 10 Comparison of Catalyst Performance

The performance of MCM-56 modified with phosphorus impregnated via ananionic precursor such as phosphoric acid (H₃PO₄) is compared withunmodified MCM-56 in Table 3 below. The data represent kinetic rateconstants evaluated based upon propylene conversion as well as cumeneselectivity measured as the amount of di-isopropylbenzene formed perunit amount of cumene produced according to the procedure outlined inExample 5. It will be seen from Table 3 that modification of MCM-56 withphosphorus (0.1-0.5 wt. %) increased its activity for the alkylation ofbenzene with propylene and that modification of MCM-56 with phosphorus(0.1-1 wt. %) increases its selectivity to cumene rather thandiisopropylbenzene (DIPB).

TABLE 3 DiPB/Cumene Catalyst Kinetic Rate Constant (wt. %) Example 5 12816.0 Example 6 140 13.1 Example 7 155 13.1 Example 8 120 14.9 Example 9 95 17.5

EXAMPLE 11 Cumene Synthesis from Benzene and Propylene Over MCM-56Pretreated Under Hydrothermal Conditions

25 g of the MCM-56 catalyst used in Example 5 were exposed to a 80/20mixture of steam and air at a GHSV of 300 h⁻¹ for 24 hours at 1000° F.One gram of the final catalyst was evaluated for benzene alkylation withpropylene according to the procedure described in Example 5, andcatalyst performance is described in Table 4.

EXAMPLE 12 Cumene Synthesis from Benzene and Propylene OverPhosphorus-modified MCM-56 Pretreated Under Hydrothermal Conditions

25 g of finished catalyst from Example 7 was exposed to a 80/20 mixtureof steam and air at a GHSV of 300 h⁻¹ for 24 hours at 1000° F. One gramof the final catalyst was evaluated for benzene alkylation withpropylene according to the procedure described in Example 5, andcatalyst performance is described in Table 4.

EXAMPLE 13 Comparison of Catalyst Performance

The performance of MCM-56 modified with phosphorous and steamed iscompared with unmodified steamed MCM-56 in Table 4 below. The datarepresent kinetic rate constants evaluated based upon propyleneconversion as well as cumene selectivity measured as the amount ofdiisopropylbenzene (DIPB) formed per unit amount of cumene producedaccording to the procedure outlined in Example 5. It will be seen fromTable 4 that the phosphorus-modified catalyst of Example 7 exhibitedsignificantly higher stability against hydrothermal deactivation thanthe unmodified catalyst of Example 5.

TABLE 4 DiPB/Cumene Catalyst Kinetic Rate Constant (wt. %) Example 5 128 16.0 Example 7  155 13.1 Example 11  10 26.0 Example 12  75 18.5

1. A process for producing ethylbenzene comprising the steps of: (a)providing a reactor with an alkylation catalyst comprising a porouscrystalline inorganic oxide material of MCM-22 and 0.5 to 5 weightpercent phosphorous; (b) supplying said reactor with benzene andethylene to produce said ethylbenzene under alkylation conditions; andwherein said alkylation catalyst has a higher selectivity towards saidethylbenzene than said alkylation catalyst that is unmodified byphosphorous under equivalent alkylation conditions.
 2. A process forproducing cumene comprising the steps of: (a) providing a reactor withan alkylation catalyst comprising a porous crystalline inorganic oxidematerial of MCM-56 and 0.1 to about 0.5 weight percent phosphorous; (b)supplying said reactor with benzene and propylene to produce said cumeneunder alkylation conditions; and wherein said alkylation catalyst has ahigher selectivity towards said cumene than said alkylation catalystthat is unmodified by phosphorous under equivalent alkylationconditions.
 3. A process for producing a monoalkylation compoundcomprising the steps of: (a) contacting an alkylation catalyst withmixture of steam and air at a temperature of up to about 1000° F. (538°C.), said alkylation catalyst comprising a porous crystalline inorganicoxide material of MCM-56 and 0.1 to about 0.5 weight percent phosphorousto produce a regenerated alkylation catalyst; (b) supplying a reactorwith an alkylatable alkylaromatic compound and an alkylating agent inthe presence of said regenerated alkylation catalyst to produce saidmonoalkylaromatic compound under alkylation conditions; wherein saidregenerated alkylation catalyst has a higher activity and higherselectivity towards said monoalkylaromatic compound than saidregenerated alkylation catalyst that is unmodified by phosphorous underequivalent alkylation conditions.